40 Edward F. Malone. 



Figures 3S to 58 were drawn as follows: 



With the aid of the camera lucida the cell outlines and as many details 

 as possible were drawn in pencil. Then under control of the microscope 

 the exact appearance of the cells was reproduced in water color. Each 

 cell is to be regarded as an individual and the spatial relations of the cells 

 in each figure do not correspond to those between the cells of the corres- 

 ponding cell group in the preparations. In these figures the cells have 

 been reproduced by combining to a certain extent different optical sections 

 of the same cell. All cells have been drawn at a magnification of 580 diame- 

 ters, and have been reproduced without reduction. Figs. 38 to 58 were all 

 drawn from cross-sections of the brains of the various animals. In Series 

 D of man the plane of section differs widely from that of a cross-section, 

 and yet (without making a careful study of this point) I was unable to 

 observe that this difference in the plane of section was correlated with any 

 difference in the appearance of the cell types here illustrated. On the con- 

 trary I can state positively that each of the above types of cells was as 

 characteristic in Series D as in Series AC, and that differences in the plans 

 of section could not possibly lead to a confusion of the different cell types. 



